Sponge-rubber liner for socket wrench



April 29, 1.958 A. BURROWS SPONGE-RUBBER LINE FOR SOCKET WRENCH FIG. 2

IN VEN TOR.

ALLEN BURROWS ATTOR N EY United States Patent SPQNGE-RUBBER LINER FOR SOCKET WRENCH Allen Burrows, Providence, R. I.

Application February 15, 1956, Serial No. 565,560

1 Claim. (Cl. 81--125) My present invention relates to an improvement in wrenches and more particularly to a lined socket wrench for spark plugs and similar articles.

A principal object of the present invention is to provide a liner which is easy to install and will compensate for variations in the inside diameter of the socket and the shape and/or size of the porcelain portion of the spark plug.

Another object of the present invention is to provide a socket wrench and liner which is simple in construction and easy and economical to manufacture and assemble.

With the above and other objects and advantageous features in view, my invention consists of a novel arrangement of parts, more fully disclosed in the detailed description following, in conjunction with the accompanying drawings and more particularly defined in the appended claim.

In the drawings:

Fig. l is a side elevation of the socket wrench and ratchet handle therefor.

Fig. 2 is an enlarged, central longitudinal section of the socket wrench with a spark plug in position.

Fig. 3 is a section taken on line 33 on Fig. 2.

Fig. 4 is a fragmentary section of a modified form of my invention.

In inserting and removing spark plugs from automobile engines it is necessary to use a tubular socket wrench which slips down over the spark plug and grasps the hexagonal metal base. A ratchet type wrench is usually inserted in the top of the socket and the spark plug can then be turned in either direction. In most engines the spark plug is sunk into the block and the metal base is not accessible with any other type of tool. To avoid strain on the porcelain parts of the spark plug,

the socket wrench is provided with a tubular chamber spaced from the body of the plug. It has been found that difficulty is encountered in picking up or inserting the loose plug. Attempts have been made to provide gripping liners which will retain the plug in the Wrench and permit it to be lifted or inserted with the wrench. These liners require special molds and usually exert strains on the porcelain.

The present invention is designed to provide a pro tective liner in a socket Wrench which will serve to grip the porcelain portions of the spark plug and to protect it against breakage. Furthermore, the liner of the present invention can be used to hold elongated bolts, rods, or other types of objects in the socket wrench.

Referring more in detail to the drawings illustrating my invention, Fig. 1 shows the conventional arrangement of the tubular socket portion which is operated by a rectangular spindle 11 and a reversible ratchet-type wrench 12. As illustrated in Fig. 2, the socket portion 10 is of tubular construction and is provided with a socket 13 at its lower end having a multiplicity of sides and adapted to grip the hexagonal base 14 of a spark plug. Above the socket portion 13 is a slightly all narrower chamber 15. The upper end of the socket portion 10 is provided with a rectangular opening 16 for receiving the spindle 11 and driving the wrench.

.In accordance with the present invention the chamber 15 is provided with a tubular liner 17 made of sponge rubber. The diameter of the liner 17 is such that it will fit tightly within the chamber 15, and it is provided with a central opening 18 which will permit the passage of the porcelain portion of the spark plug but will also serve to grip it. It is contemplated that the liner be slightly larger than the chamber so that a squeezing action is exerted when it is forced into position. In the size illustrated it has been found that an initial diameter of /2" in the opening 18 is reduced to after theliner is inserted and is highly effective for the work required.

When the socket portion 10 is pushed over a spark plug as shown in Fig. 2, the sponge rubber liner 17 will grip the porcelain portion 19 along its entire length and also tends to conform to the ribs 20. It will be noted that since the base of the porcelain 19 is wider at the bot tom, the gripping action is tighter at the bottom. This is important in preventing breakage and permitting easier withdrawal of the spark plug from the tool. After the spark plug is loosened it will lift with the tool. In inserting the plug it can first be pushed into the tool. This construction has many advantages inherent in the use of a full length sponge rubber gripping liner. Unlike other attempts, it grips the full length of the porcelain portion of the spark plug. It grips harder at the base and reduces breakage. It will handle all sizes and shapes of the porcelain portion of the spark plugs regardless of the location of the ribs or even if there were no ribs. It is more economical to manufacture and assemble since no special molds are required and it can be made out of sponge rubber tubing.

In addition to the foregoing, this type of liner does not require special machining of the socket wrench. It will fit any make or model of socket wrench within the size range. Since the liner is provided with a single uniform opening therethrough it can be used to grip bolts or other parts besides spark plugs. The unobstructed opening through the center permits the passage of long bolts and rods. It should also be noted that the general contour of the porcelain portion of the spark plug tends to taper towards the top. The gripping action of the sponge rubber is therefore hardest at the base. When the spark plug is being removed it will come out readily Without pulling the liner with it because of the over-all taper.

The form shown in Fig. 4 is designed to provide a liner which will more readily fit the different makes of wrenches on the market. It should be noted that the socket 13 is precise in its measurements to fit a particular size spark plug. However, the diameter of the chamber 15 is not critical and will vary from manufacturer to manufacturer. In this form I therefore provide the socket portion 10 with a liner 17 having a central opening 18 similar to the form shown in Fig. 2. However, the outer periphery of the liner 17 is provided with a plurality of longitudinal grooves or cuts 21 disposed at a chordal angle to provide a saw-toothed eiiect. Such a construction permits the outer portion of the liner to be squeezed inwardly on itself without distorting the internal passageway 18. This has three very great advantages. It is easier to insert by rotating in a clockwise direction while it is being pushed inwardly. It will compensate for the different diameters of the chamber 15 without altering the liner opening. it will compensate for variations in the width of the porcelain portion of the spark plug. As the spark plug is pushed inwardly the exerted pressure will be equalized between the inner Patented Apr. 29, 1958 and outer walls of theliner and tend to collapse the outer cut periphery 21 to ease any undue pressure.

I have therefore provided a simple and effective gripping liner for a socket wrench which is universal in its application and is adapted to handle not only spark plugs but other items normally driven with this type of tool. Other advantages of the present invention will be readily apparent to a person skilled in the art.

I claim:

A gripping liner for a socket wrench comprising a tubular body of sponge rubber having a central axial opening of uniform diameter extending therethrough of smaller diameter than the object being driven by the 4 socket wrench, said liner having a plurality of nonradially disposed slots extending longitudinally along the outer surface thereof to permit a decrease in the outer diameter under pressure without a decrease in the inner diameter.

References Cited in the file of this patent UNITED STATES PATENTS 1,555,2l4 Johnson Sept. 29, 1925 2,294,193 Merriman Aug. 25, 194-2 2,709,907 Robertson et al June 7, 1955 2,752,811 Wenchel July 3, 1956 

